Safety lock



. 2, 1930. T. KRoMER I SAFETY LOCK Filed Feb. v29, 1928 /F'gn 7 /m/en for.' Vga- '23 Patented Dec. 2, 1930 UNITED STATES THnoDoR KROMER, on FREIBURG, iN BREIVSGAU, GEMANKASSIGNQRTO THEoDoR' KROMER GESELLSCHAFT MIT BESCHRNKTERJHAFTUNG, .or FREIBURG, IN BREIs- GAU, GERMANY "'VsAFETYLocK i Application led February 29, 1928,'Serial No. 258,073, and i'n Germany .Tune 3, 1927.-

My invention relates to that class of locks which can belopened by means' of a handle 1agiter setting up a secret combination of Asym-V ols. to keep the lock spindle outside the operative reach of the members which allow the bolt to be shifted, until 'the combination oit' symbols has been set up and so to increase the security of the 'lock against unwarranted opening. This end is obtained by the means explained below with reference to the accompanying drawing. In the latter:

Fig. l represents a. vertical section passing through the lock spindle;

Fig. 2, a view of the lock from behind, with cover plate removed; A

Fig. 3, a similar view, the bolt being removed,

Fig. 4, a further view of the inside of the lock with the dividing wall omitted;

Fig. 5, a view of a detail; f Figsl 6 and 7 are two opposite views of a detail; and

Fig. 8, a cross-section of the same. In the drawing, l denotes the rotatable, axially adjustable lock spindle which carries'a handle 2 in the form ofa knob. In,` anV enlarged part 3 of thelock spindle,ltwo

y pins 4, 5 are adjustably mounted on `springs 6 in radial recesses. Accord-ing to the axial position of the spindlel, these pinscome j into engagement with locking discs 7, 8 or`` 8, 9, by engaging in notches in the setting discs 10 which, by being rotatably adjustable in the locking discs, are capable of eiecting` the change of the combination. With the.'

teeth of each of the setting discs engage two follower pins Vl2, under the iniiuence of' springs 11, and produce the connection with Ythe corresponding locking discs. A The outermost setting discs lOl have eccentric inner.

edges 13 which terminate in V"shoulders 13a adapted, on a right-hand rotation oi" vthe spindle, to be engaged by pins 4 rand 5 for.

setting the locking discs. The centre disc 170 has a notch in which one of the` pins always engages, irrespective of the position of the spindle. By pressing in the lock spindle in the direction indicated by the arrow in Fig. l, and by rotating the spindle to the What I kpropose by my invention is V'rotated to the right,the'pin 5 effects ,they set.- ting of the disc 9. When the locking'discs v7, .9 have been thus set up, the disc 8 which,

right, the lockingldisc can be: set `by means l .of the pin4 which engagestheshoulder 13a of, vthe corresponding'- setting disc while, when the spindle lis pulled back and again as-previously stated, always remains in engagement with one of thefplns, can be set by-turning the spindle to `the leftV so as not to vdisturb the setting Vof the discs 7 and 9.

i By turning the ,spindlefl tothe left the pins ,4 or vgcannot get inoperative engagement with Vany of the shoulders 13a of the setting Y discsl() and, sliding on the eccentric edges 13, the pins Vare forced into the radial recesses of spindle 1 against the action. of the `springs 6. VThe middle locking disc 'has a toothed periphery 14, with which engages a fdetent pin 15 which is Vunderithe iniluence of a spring and servesfto secure the locking disc in the proper position when being set. Therounded end ofthe pinsll, 5 and the Y i bevelled edges l'of the axial bore ofY the setting discs l0, ensure Aan easyl axial displacement of 'the spindle ,Land render any tampering with the combination diiicult. A wall. 17 dividing thelockV casing has a recess 18 to vcarry-a.circularflange1901i the' .setting discY that projects over locking "disc 7.A A locking lever v22 is mounted on a pivotV 21itted in recesses in the 4lock bottom'and cover -and projecting through the gap 2O` of partition wall 17. Aflat spring23 secured vto the pivot21,carries a locking mem- 4ber24A which, together with spring 23, pene- Vtrates throughthe gapyin the partition wall vandfdr'op's into notches25 in the locking discs v after saidnotches have been aligned by the 'setting o-thegdiscs. i The lever22 has Aa "nose: 27 which' lnormally bears against one ofthe boltguidingpins 26. It hasV also a circular opening-28 which, :when the member 21.1L

.drops into the notches 25, and owing to the penduluous suspension of the lockingllever, passes immediately in front of the spindle l and permitsthe flattened extremity 29 of theV spindle tol enter `a correspondingly ,shaped opening in an eccentric 30 whereby v the lock bolt 33 is operated.

A disc 31, which is secured to the spindle l and which moves within a recessed escuteheon 32 on the door, may carry the symbols with reference to which the different lock colnbinations are set up.

It is important that, on retracting the bolt 33 from the sheet position, the setting of the locking discs 7, 8, 9 should be disturbed. For this purpose the discs 7, 8, 9 are turned by rotating the spindle l to the right. Only after the discs 7, 8, 9 have been turned the spindle 1 is displaced axially so as to reenter the eccentric 30 for withdrawing the bolt 33 from its shut positionby a further turning of spindle 1. By the lirstsaid r'otation of spindle l the locking member 24 is forced out ot the notches 25. Hence it is impossible to find out the combination when the lock is open. The locking discs may be displaced, and the member 24 forced out of the notch 25 in spite of the lever 22 being held fast by the spindle l, owing to the resilience of the spring 23.

The securing of the lock with the bolt in shut position is effected, after pulling bach the spindle l, by turning the locking discs to the right so as to force the locking member 24 of the lever 22 out of the notches 25 whereby the lever 22 is moved to the opening 28, being displaced with reference to the spindle l, the latter being prevented from engaging the bore of the eccentric 30.

I claim:

l. In a lock, the combination with a. lock bolt and with an operating element for the same, of a rotatable lock spindle adapted to be axially displaced for engagement with and disengagement from said operating element, a pivoted blocking lever adapted to enter the passage between the spindle and said operating element, a plurality of discs mounted on the spindle, a `resilient controlling arm on the lever resting on the discs and maintaining the lever normally in `blocking position, the discs being provided with peripheral notches into which, when in alignment, the arm can drop so as-to release the lever, and means on the spindle whereby the latter can be used for settingthe discs in lever-releasing position. i

2. A structure as claimed in claim l, wherein the disc-setting means consist of spring-controlled pins mounted in the spindle and adapted to engage shoulders on the .inner edges of thediscs, said inner edges being bevelled so as to enable the pins .to slip easily from one disc to another on an axial displacement of the spindle.

THEoDoR ,KROMER' 

